U.S. Patent Application Publication No. 2012/0111185, which is hereby incorporated by reference in entirety, discloses a high efficiency diametrically compact, radial oriented piston hydraulic machine. The machine includes a cylinder block with a plurality of cylinders coupled to a first port by first valve and to a second port by a second valve. A drive shaft with an eccentric cam is rotatably received in the cylinder block and a cam bearing extends around the eccentric cam. A separate piston is slideably received in each cylinder. A piston rod is coupled at one end to the piston and a curved shoe at the other end abuts the cam bearing. The curved shoe distributes force from the piston rod onto a relatively large area of the cam bearing and a retaining ring holds each shoe against the cam bearing. The cylinder block has opposing ends with a side surface there between through which every cylinder opens. A band engages the side surface closing the openings of the cylinders.
U.S. patent application Ser. No. 13/343,436, which is hereby incorporated by reference in entirety, discloses a radial piston pump having a plurality of cylinders within which pistons reciprocally move. Each cylinder is connected to a first port by an inlet passage that has an inlet check valve, and is connected to a second port by an outlet passage that has an outlet check valve. A throttling plate extends across the inlet passages and has a separate aperture associated with each inlet passage. Rotation of the throttling plate varies the degree of alignment of each aperture with the associated inlet passage, thereby forming variable orifices for altering displacement of the pump. Uniquely shaped apertures specifically affect the rate at which the variable orifices close with throttle member movement, so that the closure rate decreases with increased closure of the variable orifices.